Vibration absorbing centrifugal clutch



Oct. 27, 1936.

D. GREGG 2,058,440 VIBRATION ABSORBING CENTRIFUGAL CLUTCH Filed Aug. 12,1931 2 Sheets-Sheet l INVENTOR v Dawa Gregg ATTORNEY Oct. 27, 1936. D.GREGG VIBRATION ABSORBING CENTRIFUGAL CLUTCH Filed Aug. 12, 1931 2Sheets-Sheet 2 INVENTOR flawd Grqyy I ATTORNEY Patented Oct. 27, 1936HTED STATES VIBRATIDN ABSORBING CENTRIFUGAL CLUTCH David Gregg,Caldwell, N. J., assignmto Bendix Research Corporation, East Orange, N.J., a

corporation of Indiana Application August 12, 1931, Serial No. 556,685

14' Glaims. 192-403) .This invention relates to a novel driving meansfor engine accessories and is illustrated in embodying an enginesupercharger driving mechanism.

An object of the invention is to provide an accessory driving mechanismin which the torque capacity is substantially equal to that required todrive the accessory under normal driving conditions and which shieldsthe accessory from m abnormal forces and loads.

Another object of the invention is to provide an engine accessorydriving mechanism which dampens the vibrational forces that otherwisewould be transmitted between the engine and the 5 accessory.

,Another object of the invention is to provide a high speed drivingmechanism for an engine accessory that reduces the driving forcefluctuations either of momentary or extended duration.

Another object of the invention is to provide a driving mechanism for anengine accessory in which a unitary device is included that functions asa centrifugal clutch, as a flexible joint, and as a vibration dampener.

Another object of the invention is to provide a centrifugal clutch foran engine accessory that acts as an overload release and a vibrationdampener.

Another object of the invention is to provide a a driving mechanism foran engine supercharger that has a torque capacity which varies with thesupercharger speed and which has inherent vibration dampeningcharacteristics irrespective of the accessory speed.

Another object of theinvention is to provide a driving mechanism for anengine accessory in which the accessory may be driven at two differentspeed ratios and in which the driving mechanism is adapted to dampen thevibrational forces which 40 otherwise would be transmitted between theengine and the accessory.

Other valuable features of the invention will be apparent from thefollowing description of a preferred embodiment which has beenillustrated 45 in the accompanying drawings, in which:

Fig. 1 is a vertical cross-section of an engine supercharger having adriving mechanism con- 'structed according to the present invention;

Fig. 21s an enlarged sectional view of the im- 50 proved clutch; and,

Fig. 3 is a sectional view taken on the line 3-3 o F For illustrativepurposes, the novel driving mechanism has been shown in connection with55 an engine driven supercharger. A portion of the engine crank case isshown at it, in which is rotatably mounted the engine crank shaft lloperatively connected to driving gear l2 by any desired means, such asplate I 3, having a toothed connection with gear I! at It. Hollowdriving 5 shaft I6 is rotatably mounted in suitable bearings and iii inthe supercharger housing and carries fan blades l9 and impeller 2| forimparting velocity and pressure to air or other gases entering thesupercharger at inlet 22, from 10 whence it is forced outwardly throughdischarge passage 23 tothe cylinders of the engine (not shown).

Gear I2 is meshed with pinions 24 and 26 respectively, each of which isthe driving gear for an intermediate gear train between crank shaft IIand supercharger shaft is. Gear 24 is the driving member of the slowspeed geartrain and is rotatably mounted in the transverse web member 21in the housing 28 of the supercharger transmission gearing. The othermembers of the slow speed gear train include gear 29 secured to gear 24by shaft 3| through the intermediary of an overrunning clutch 32, whichpermits gear 29 to receive torque from shaft M in one direction only andoverrun the shaft if torque be applied in the opposite direction.

Pinion 33 secured to supercharger shaft i6 is in constant mesh with gear29, and in the normal slow speed running of the supercharger 30 thepower is transmitted from gear l2 to pinion 24 and is transmittedtherefrom by shaft 3| through overrunning clutch 32 to gear 29 andsupercharger pinion 33.

Pinion 26, as hereinbefore stated, is also meshed with gear l2 and issecured to shaft 42 which is rotatably mounted in web 21 by bearing 31,the outer end of shaft 42 being operatively connected to clutch gear 38,the construction of which will be hereinafter more fully described, itbeing suf- 4O ficient at this point to state that in the opera-J tion ofthe supercharger by the slow speed mechanism, the clutch gear 38 isdisconnected from shaft 42.

The clutch gear generally designated by 38 is meshed with shaft pinion39 and frictionally driven by a hollow shaft 42 splined or otherwisesecured to pinion 26. Hollow shaft 42 is provided with a radiallyextending disc 43 integral with or otherwise secured thereto and onopposite 5 side of which are annular frictional members 44 havingfibrous or other suitable faces 45 in frictional contact with the disc43. Clutch housing 4! is mounted on hollow shaft 42 by bearing 49 and inthe transmission case by bearing 5| and preferably locates the annularfriction members 44 by contacting with their periphery at 52. Clutchgear 38 has its web or wall 53 extended inwardly to provide a supportingsurface 56 having a frictional contact with the outer surface offriction member 44. At the opposite side of the clutch gear a clearancespace 61 is provided, within which is slidably mounted an annularpressure member 62 to which are secured pins 63 slidably mounted insuitable openings formed in the outer wall 41 of the clutch gear.Friction members 44 are also provided with axially extending projections61 which extend between the spaced legs of U-shaped springs 69 which maybe laminated, if desired, and are positioned on the housing wall 41 byaxially extending pins 1| and 12 secured to the gear housing in anydesired manner. Centrifugal weights 14 are pivotally mounted on the gearhousing at 1.5 and arranged to be thrown outwardly by centrifugal forceto contact with pins 63 and force pressure member 62 toward supportingface 56 and clamp disc 43 and annular members 44 between the pressurering and the opposite face of the gear housing, the side walls 53 and 41and toothed rim 18 of which form an enclosure for all of the frictionalmembers.

Inwardly extending projections 8| are provided on weights 14 which areadapted to contact thrust collar 82, which may be moved toward the leftas shown in Fig. 1 by manually operated lever 83 and rotate weights 14about the pivotal points 15 to disengage the housing from shaft 42during the operation of the supercharger by the slow speed gear train.

In the operation of the supercharger, impeller 2iis driven by the slowspeed gear train, hereinbefore described, up to any desired enginespeed, it being understood that during the low speed gear operationthrust collar 82 is in position to holdcentrifugal weights 14 in theirinner position and prevent the engagement of clutch gear 38 with itsdriving shaft 42. Under conditions of low altitude or comparatively highbarometric pressure, the low speed driving train may be sufficient toenable the engine to maintain its desired power, but under lowbarometric pressure, it may be desirable to increase the superchargerspeed, and under these conditions, thrust member 82 is moved toward theright by manually operated lever 83 and weights 14 are released and maybe thrown outwardly by the rotating clutch gear38, which is in constantmesh with pinion 38 secured to the supercharger shaft l6. Outwardmovement of the weights forces pressure ring 62 v inwardly to clamp disc43 between the annular friction members 44 and connect clutch gear 38 tothe driving shaft 42.

Increased speed of the supercharger causes the centrifugal force ofweights 14 to be increased and exert additional pressure upon thefriction members, and with a suitable selection of weights andleverages, the torque capacity of the clutch gear 38 increases insubstantially the same ratio as the driving torque of the superchargerincreases.

. It is desirable that the frictional surfaces of pressure member 82 andpressure plate 56 be selected with frictional coefflcients of such valuethat slippage will occur between the frictional members 44 and thepressure plate 62 or pressure surface 56 prior to slippage between themembers 44 and disc 43, which arrangement enables the inner surfaces toact as the main driving members and the outer surfaces to act as avibration device.

With the foregoing ratio of frictional coemcients, the inner frictionmembers would not operate satisfactorily as driving members if someprovision were not made for limiting or restraining the relativemovement of the outer members, and -to counteract this tendency, theU-shaped springs are disposed between the gear housing and theprojections 61 on the friction members 44 which tend to hold the outerfriction members in the position illustrated in Fig. 2 and to restorethem to this position when they have been displaced by variations indriving torque which ordi narily arise from torsional vibration ineither the engine or supercharger shafts. These variations in torque areusually ofmomentary duration and occur in both directions, eitherdirection of movement being counteracted and restrained by the flexingof the U-shaped springs 59.

Any suitable device, such as motor 9|, may be used as a convenient meansfor starting the engine through gears 92 and 93, the construction of thestarting device being well known and forms no part of the presentinvention.

It will be readily understood by the foregoing description that a noveltransmission mechanism for a supercharger has been provided by which thesupercharger or other engine accessory may be driven selectively by twogear trains having relatively different gear ratios.

it will also be understood that a change in gear ratios may be readilymade by operation of the manually operated lever 83 which will releasethe centrifugal weight 14 and drive the supercharger atan increasedspeed, the low speed gear train being rendered inoperative by the'overrunning clutch 32. The torsional vibration is not as prevalentduring low speed operation as in high speed operation, and therefore thevibration dampening centrifugally operated clutch is only incorporatedin the high speed train, but if desired, a similar mechanism may be usedin connection with the low speed driving mechanism which will alsorelieve the driving members from the forces due to torsional vibrationand provide a driving means in which the torque capacity issubstantially proportional to the speed of the supercharger.

While a preferred embodiment of the invention has been illustrated anddescribed, it is understood that this showing and description areillustrative only, and that the invention is not regarded as limited tothe form shown and described, or otherwise, except by the terms 'of thefollowing claims:

What is claimed is:

1. In a friction clutch for connecting a driving element to a drivenelement, two pairs of friction surfaces of different torque capacitiesarranged in series, resilient means opposing relative movement of thesurfaces having the less capacity, and common means for increasing thecontact pressure on all of said surfaces as the speed of the clutch isincreased.

2. Ina friction clutch for connecting a driving element to a drivenelement, two pairs of friction surfaces of different torque capacitiesarranged in series, resilient means opposing relative movement of thesurfaces having the less capacity, and means for increasing the torquecapacity of both pairs of surfaces as-the speed of the clutch isincreased.

3. In a friction clutch for connecting a driving element to a drivenelement, two pairs of friction surfaces of different torque capacitiesarranged in series, means for limiting relative movement of the pair-ofsurfaces having the less torque capacity and'centrifugal weightsrotatable with the clutch adapted to increase the contact pressure onall of said surfaces as the clutch speed is increased.

4. In a friction clutch for connecting a driving element to a drivenelement, two pairs of friction surfaces of different torque capacitiesarranged in series, means for limiting relative movement of the pair ofsurfaces having the less torque capac-. ity and centrifugal weightsrotatable withthe clutch adapted to increase the friction of both pairsof surfaces as the clutch speed is increased.

5. In a clutch for connecting a driving element to a driven element, thecombination of a friction member adapted to be secured to one element, asecond friction member coacting with the first member, a housing for themembers adapted to be operatively connected to the other element, a

third friction member slidably secured to the housing coacting with thesecond friction member, means for resiliently opposing relative movementbetween the second andthird friction members, and means rotatable withthe housing and projecting externally thereof for varying the contactingpressure of the friction members.

6. In a clutch forconnecting a driving element.

to a driven element, thecombination of a friction member adapted to besecured to one element, a second friction member coacting with the firstmember, a housing for the members adapted to be operatively connected tothe other element,

a third friction member slidably secured to the housing coacting withthe second friction member, means for resiliently opposing relativemovement between the second and third friction members, and centrifugalweights pivoted on the cured to the housing by axially slidableprojections, said second member being resiliently-se-- cured to thehousing by spring members adapted to limit relative movementtherebetween, and said housing being adapted to be connected to theother of said elements.

8. In a clutch for connecting a driving element to a driven element, thecombination of a friction member adapted to be secured to one of saidelements, a second friction member coacting with the first member, athird friction member coacting with the second member, a housing for allfriction members, said third member'being secured to the housing byaxially slidable projections, said second member being resilientlysecured to the housing by spring members adapted to limit relativemovement therebetween, said housing being adapted to be connected to theother of said elements, and centrifugal weights on said housing adaptedto increase the pressure of all members as the speedof the housing isincreased. V x

9. In a clutch for connecting a driving element to a driven element, thecombination of a disc adapted to be secured to one of said elements,

a pair of annular friction rings slidably disposed on opposite sides ofsaid disc, a housing rotatable with respect to said rings, said housinghaving a radial wall contacting the outer face of one of said rings, anannular pressure member axially slidable in the housing toward the ringsand retatable with the housing, spring means resiliently connecting therings to the housing, and means for varying the pressure of the ringsagainst the disc by sliding the pressure member toward the housing wall.I

10. In a clutch for connecting a driving element to a driven element,the combination of a disc adapted to be secured to one of said elements.a .pair of annular friction rings slidably disposed on opposite sides ofsaid disc, a housing rotatable with respect to said rings, said housinghaving a radial wall contacting the outer face of one of said rings, anannular pressure member axially crease the friction between the ringsand disc as the speed of the housing is increased.

11. In a clutch for connecting a driving element to a driven element,the combination of .a plurality of friction members for co'nnectingtheelements, including two pairs of contacting fric- I tional surfaces ofdifferent torquecapacitiesarranged in tandem, means for-limitingrelative movement between the surfaces of less torque capacity, andmeans responsive to the speed of the driven element for increasing thetorquecapacity of both pairs of the frictional surfaces with an increasein the speed ofthe driven element.

12 In a clutch for connecting a driving element to adriven element,the-combination of a friction disk, 9. housing'having friction surfaceson opposite sides of the disk, a floating member interposed between thedisk and each of the surfaceshaving limited movement relative to thehousing, the floating members having different frictional contact withthe housing than with the disk,

and means for resiliently'opposing movement of the floating membersrelative to the shaft.

13. In a clutch for connecting a driving element to a driven element,cooperative friction members adapted to be connected to the'driving anddriven elements respectively, additional friction mermbers arranged intandem with the first mentioned members, said additional frictionalmembers having friction coefficients of less value than those of thefirst mentioned friction members and having limited relative movementwith respect to the first mentioned friction members for dampeningvibration, and centrifugal means rotatable with the clutch for clampingall of said friction mem bers together.

14. In a clutch for connecting a driving element to a driven element,the combination of driving and driven friction members, said membershaving two pairs of friction surfaces of difierent torque capacitiesarranged in tandem, means for limiting relative rotative movement of thesurfaces having the less torque capacity, and centrifugal weightsrotatable with the driven members and responsive to the speed thereof,said weights being arranged to force all of the friction memberstogether and increase the torque capacity of both pairs of surfaces whenthe. speed of the driven members is increased.

DAVID GREGG.

